Implantation of an implantable penile prosthesis (IPP) is a common surgical procedure for treating erectile dysfunction and other penile ailments. Typically, an IPP comprises at least one inflatable cylinder connected to a pump with an integrated reservoir containing a quantity of fill liquid. In other versions, an IPP can alternatively comprise an inflatable cylinder connected by a pump to a separate reservoir for holding the quantity of fill liquid. Commercial IPP devices are available under the trade names AMBICOR and AMS 700 from American Medical Systems of Minnetonka, Minn. The entire prosthesis assembly is implanted into the patient's body with the inflatable cylinder being placed in the corpus cavernosum and the pump being placed within the scrotum. The reservoir can also be placed within the scrotum or placed elsewhere within the pelvic region. To operate the IPP, the pump is actuated to transfer fill liquid from the pump into the inflatable cylinder to fill and pressurize the inflatable cylinder.
Conventional inflatable cylinders for IPPs operate by filling the typically hollow inflatable cylinders with a pressurized fill liquid to simulate an erection. The inflatable cylinders are generally defined by an inner tube and an outer tube, wherein the inner tube generally includes the reservoir that receives the pressurized fill liquid so as to transform from a flaccid to an erect state simulating an erection. The outer tube generally functions as a containment member for the inner tube and is used to prevent fluid migration out of the inflatable cylinder in the event of a structural failure of the inner tube.
To further limit the potential for structural failure of the inner tube, conventional inflatable cylinders include an elastic fabric sleeve placed over the inner tube so as to be positioned between the inner tube and the outer tube. In a relaxed state, the elastic fabric sleeve generally fits snugly over the inner tube. Upon introduction of the pressurized fill liquid into the inner tube, the inner tube extends to an erect state and expands in girth, whereby the elastic fabric sleeve is also caused to expand in girth. As the girth of the elastic fabric sleeve increases, the elastic fabric sleeve resists expansion and applies pressure to the inner tube. This pressure helps to prevent the inner tube from expanding beyond a desired limit so as to reduce the potential for failure of the inner tube. When the pressurized fill liquid is to be removed from the inner tube, the elastic fabric sleeve applies pressure that helps to vent and force the pressurized fill liquid from the inner tube such that the inner tube and the elastic sleeve return to their normal, uninflated state. The elastic sleeve is frequently constructed from elastic materials such as those commercially available under the trade names Spandex and Lycra.
A potential disadvantage of the elastic sleeve is that over time and following numerous expansion cycles, the potential exists for the elastic fabric to begin wearing and creating weak spots in the elastic sleeve, such as at locations of a fold. When such wear occurs and weak spots are formed, the potential exists for the inner tube to swell and potentially burst at such a weak spot. This can result in a potential aneurysm where the pressurized inflation fluid is able to escape the inflatable cylinder and to be introduced into the corpus cavernosum. As such, it would be advantageous to have an improved sleeve design that reduces the potential for aneurysm.